An abrasive manufacturing process involves the application of an abrasive article to a workpiece to polish, grind, or otherwise remove material from the workpiece. In many processes it is desirable to control the amount of material removed from a workpiece. It is, for example, often desirable to remove material at a constant rate, i.e., to achieve a constant rate of cut with the abrasive article. That is, it is often desirable to remove a relatively constant amount of material from the workpiece over a period of time. In other cases, it is desirable to remove a fixed amount of material from a workpiece. In either case, it is desirable to control the amount of material removed even as the abrasive article wears.
One common way for controlling the amount of material removed from a workpiece is to force the abrasive article into the workpiece at a constant rate. In other words, a machine may be used within the process to physically move the abrasive article into the workpiece at predefined increments. These machines often tend to be heavy, rigid machines that are expensive to construct and maintain. Moreover, such machines are limited to well-defined workpiece geometries, and can easily damage a workpiece. The workpiece may be damaged, for example, if the machine unexpectedly contacts the workpiece while rapidly advancing the abrasive article.
Other abrasive manufacturing processes make use of feedback controls, either manual or automated, to control the amount of material removed from a workpiece. For example, some abrading machines incorporate sensors to measure an amount of material removed from the workpiece, and may adjust process variables, e.g., an application force of the abrasive article, coolant flow, an abrasion time, a velocity of the abrasive article relative to the workpiece, and the like, based on the measurements. Alternatively, an operator may measure the abraded workpiece or the removed material, and make manual adjustments to one or more process variables based on the measurements in an attempt to achieve a constant rate of cut of the workpiece.
In general, the use of manual measurements and adjustments is prone to error, and can easily lead to the production of unacceptable workpieces. The use of feedback loops and automated controls, however, can add significant expense to an abrasive manufacturing process. Moreover, such systems may be limited to particular types of workpieces, and may not easily be used on different types of workpieces.